into the Cause of Voltaic Electricity* 295 



of times at considerable intervals, I found a great difference 

 in the effect resulting from the larger or smaller number of 

 pairs. Thus in the first experiments were obtained, with two 

 pairs, 53° of Breguet's helix; with four pairs, 75°; with six 

 pairs, 97°; and in the latter experiments were obtained, with 

 two pairs, from 1 1° to 12° ; and with six pairs, from 5° to 6°. 

 The following experiments were made with a slightly acid 

 solution, and show the rapidity with which the intensity of 

 the current diminishes according to the number of pairs. 

 At the instant of immersion two pairs gave 50° of Breguet's 

 helix, but at the expiration of a minute they only gave 30°; 

 fourteen pairs perfectly similar gave at the first instant 35°, 

 but at the end of a minute their effect was reduced to 10°. 

 When the solution had lost nearly all its acidity, two, four, 

 eight, and sixteen pairs, all gave 20° at the moment of im- 

 mersion, but their effect underwent a diminution, the quan- 

 tity and rapidity of which corresponded to the increase in the 

 number of pairs. 



We proceed to inquire how the preceding results are to be 

 reconciled with our theory of the pile. 



In all the experiments which have been described the sur- 

 face of the pairs remains constant, their number alone varies; 

 it is therefore evident, from what has been said, that the quan- 

 tity of -electricity produced at each of the poles is always the 

 same, but that the two electricities accumulated at the two 

 poles reunite in a larger or smaller proportion through the 

 pile. So soon as, by sufficiently increasing the number of the 

 pairs, we have succeeded in causing nearly the whole of the 

 two electricities to pass, in order to reunite, by way of the 

 conductor, in preference to that of the pile, the limit is at- 

 tained beyond which nothing is gained by adding to the num- 

 ber of pairs. It may therefore easily be seen why this limit 

 will be so much the sooner attained, in proportion as the 

 bodies interposed between the poles are better conductors, 

 and on the contrary the liquid of the pile a worse conductor. 

 But why, by increasing the number of pairs beyond the limit, 

 is the intensity of the current diminished ? It would appear 

 that neither diminution nor augmentation should be effected. 

 To explain this result it- must be observed that when the che- 

 mical action of the liquid upon the oxidable metal of the pair 

 is lively and prompt, it develops quantities of electricity upon 

 each pair, sufficiently considerable to be regarded as sensibly 

 equal in the same time, allowing that the small differences 

 which exist among them disappear when they are compared 

 to the absolute quantities themselves. The result therefore 

 is, that all the pairs being nearly of the same strength, an in- 

 crease in the number of pairs would not have any influence 



